<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>my html 5</title>
    <link rel="stylesheet" href="mycss.css">
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css">
</head>
<body>
<h1>云计算</h1>
<form action="">
    <input class="btn btn-primary btn-lg" type="submit">
</form>
</body>
</html>